Eric -
I would suggest 7075-T6 aluminum as its hard, but easily machined. SS is female dog to work with as well as heavy.

The R80 is more problematic in mounting lights as it doesn't have the Roo Bars the R100 has. If you frame mount or on the cylinder guards too low they don't give you the look-ahead coverage you want. I suggest you machine a mount that clamps on the forks between the top and bottom brace. Not only can you aim them with the forks - you can reach out and point them on the fly. That's what I did on my PD off the Roo bar.

Piaa lights are an absolute - unequivocal waste of money. There advertising is right on the edge of lying and rippoff. You are served better with inexpensive, replaceable driving lights that have the lummens and pattern you want. The Optilux 1500 or 1400 (Hella) sell for around $35 and you won't cry like a baby when you drop the GS and break them. I have the 1500 on my GS in the photo, but they may have been discontinued/replaced with another model. Put SilverStar bulbs in them and the light is in the spectrum you want and clear. Put your money in other improvements.

Why build another top clamp, you've got a good one to work with? Since you have the tools to make one, just finish out what you have. Radius the edges and get rid of all the extra bulk on it and it'll do just fine.

Maybe i'll do as you say. However, I still need to see exactly what that clamp looks like once dissassembled.
But it sure can look better...
For the driving lights, the Piaa look good....However, I've been using a set of driving lights you can see on my Transalp (I don't remember the brand name...) and have another set on a shelf. I'm not gonna use Piaa just for their good look.

Ho! I like the sound of that engine....and I just HATE the side stand!

I welded a few tabs on my crashbars to mount Hella driving lights. They light up well but I've have some problems with blowing bulbs when I wreck. It happens more often than you'd think

I don't recommend mounting the lights this low. They don't point down on the road well enough. Ripples in the asphalt become 40' sections of shadow that can hide anything. Mounting them higher up like on the roo bar that Toaster Tan shows is a much better idea.

Looks like the PO solved the indicator mount problem by flipping the brackets over and moving them to the other side - if you use the SJBMW non G/S item that is all that is required.

I dont think the side panels, clock and rev counter were always stock fitment, and they are NLA and expensive. - a rev counter just sold for $305- on ebay.

I like Avon Distanzas, as good as anything else on the black top and OK on gravel tracks, but I dont do mud or sand with them.

My 86 G/S PD doesnt have the circlip, and as a word of advice dont ever be tempted to fit anything other that loose C3 bearings in the rebuild - the guy who rebuilt the box on my G/S used stock bearings and some got so hot they were turning on the shafts-----.

I have used a tubular lower brace on my well worn G/S it made a noticable improvement, but you could see the forks twist before I fitted it.

The 3 bolt rear wheels are hard to find, and for some reason I havent found one that doesnt have the drum worn almost to the limit, so getting a spare was a good deal.

Dont fret too much over the compression - it gives you a good excuse to fit a pair of 1000cc barrels anyway.

I won't be fitting side-panels. Since they didn't originally come with this bike.
I'm not gonna pay that much for a eom rpm dial. I'll probably just get some after-market electronic indicator like I've been using on my Transalp.

I don't think it would be a "sacrilege" to fit a black solo-seat. But before I begin spending money...I'm taking the old ladie to a private mechanic who specialises in those old BMW. He installed a small shop in his garage. I'm a good enough "mechanic" to know when I should not touch something. This guy will check the engine and replace what needs to be.
I won't be riding the bike before the end of winter...in April? So plenty of time!

I welded a few tabs on my crashbars to mount Hella driving lights. They light up well but I've have some problems with blowing bulbs when I wreck. It happens more often than you'd think

I don't recommend mounting the lights this low. They don't point down on the road well enough. Ripples in the asphalt become 40' sections of shadow that can hide anything. Mounting them higher up like on the roo bar that Toaster Tan shows is a much better idea.

Also - create a mount that can rotate. Mine are mounted on the Roo bar with a rubber wrap under the clamp. I can reach out and rotate the lights down so if I'm off road riding and the bike goes over the lights don't impact. They are used for night driving so don't need them when I'm in the rough. Surprisingly, I got them tight enough to stay put on rough roads, but still loose enough to rotate them down. No tools required and on the fly.